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Caon J, Paquette M, Pickles T. Statin and ASA Use in Regards to Comorbidity and Outcome in Men with Prostate Cancer Treated with Curative Intent Radiation Therapy. Int J Radiat Oncol Biol Phys 2011. [DOI: 10.1016/j.ijrobp.2011.06.687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Berrang T, Paquette M, Woods R, Speers C, Hayshi A, Lerch L, Walter C, Smith S, Olivotto I. Can We Predict Which Women with a Negative Sentinel Lymph Node Biopsy Are at High Risk of a False Negative Result? Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-09-303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Standard of care for women with a positive sentinel lymph node biopsy (SLNB) is to have a completion axillary lymph node dissection (cALND). For women with a negative SLNB, cALND is often not performed, accepting that a proportion will have a false negative (FN) result. FN rates are commonly reported based on surgeon experience. In the absence of cALND, information on FN rates will not be available, and other means of assessing the risk for FN SLNB is needed.Materials and Methods: Between May 1999 and December 2006, 1661 women with early-stage breast cancer that had undergone SLNB followed by cALND, were identified from our provincial database: 77 FN, 560 true positive (TP), and 1024 true negative (TN). FN cases were matched 1:3 with TN cases by date of SLNB. Chi-square and Wilcoxon Rank-sum tests were used to screen variables and those with moderate association were identified and included in subsequent models. Logistic regression was used to develop a multivariable model to predict the probability of FN vs. TN status. ROC curves were used to estimate the optimal probability cut-off, at which sensitivity (SN) and specificity (SP) were maximized. The model's performance was then assessed using a cross-validation technique.Results: Factors examined that did not significantly affect FN vs. TN status rate included: age, body mass index, previous breast surgery, histology, estrogen receptor status, margin status, tumor palpability, injection technique (peritumoral, periareolar), mapping agent used (yes/no), and SLNB done pre vs. post breast surgery (all p=NS). Factors identified that significantly affected FN vs. TN status (p<0.05) and thus included for potential use in the model included: tumor size, tumor grade, lymphovascular invasion (+/-LVI), tumor site (central/medial, lateral, other), type of breast surgery (mastectomy vs. lumpectomy), pre-operative lymphoscintiscan (yes/no), colloid (yes/no), number of SLN (1 vs. >1). The final model contained 5 variables: T stage (1 vs. 2), tumor grade, number of SLN removed, tumor site, and LVI. ROC identified an optimal probability cut-point for this model of 0.217 (21.7% risk of FN) with a corresponding SN of 71% and SP of 70%. In the cross-validation, the model correctly classified 66% of cases (SN of 73%, SP of 64%) with an AUC of 0.76. With increasing FN risk, SN declined and SP increased such that at a FN risk of 30%, this model had a SN 56%, SP 77%, and accuracy 72%. Using this model a woman with a T1, lateral, grade 3, 1 SLN and LVI- had a predicted FN risk of 21.5%, increasing to 52.2% if she were LVI+.Discussion: For women with early breast cancer, a negative SLNB result has a significant impact on prognosis and recommendations for further systemic and radiation therapy, this model (T size, tumor grade, number of SLN removed, tumor site, and LVI) is the first that would offer a quantitative prediction of FN risk in this setting, which could influence further discussion and therapeutic decision making. Potential refinements of this model will be explored, incorporating 'lower-priority' variables.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 303.
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Paquette M, Plante I, Labrecque G, Beauchamp D, Thibault L. Dietary composition alters gentamicin-induced nephrotoxicity in rats. Physiol Behav 2002; 77:141-50. [PMID: 12213512 DOI: 10.1016/s0031-9384(02)00848-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Previous studies have shown temporal variations in gentamicin-induced renal toxicity characterized by a peak when administered during the resting period and a trough during the active period. This time-dependent toxicity was also altered according to the macronutrient composition of dietary regimens offered to female rats. In the present study, adult female Sprague-Dawley rats were adapted to semipurified isocaloric diets containing 20% casein or soy-protein (10% fat each) or to a standard chow diet (18.1% mixed proteins; 4.5% fat). The animals were then chronically treated for 10 days with a nephrotoxic dose of gentamicin sulfate (40 mg/kg/day ip) or a saline solution administered in the middle of their resting period (1200 h) or in the middle of their activity period (0000 h). Body weights of rats injected in the middle of their resting period decreased over the last 6 days of gentamicin treatment. Total 12-h light and 12-h dark food intakes were decreased in gentamicin-treated rats. Rats fed the standard chow diet had significantly lower corticocellular regeneration, serum creatinine and blood urea nitrogen compared to those fed the casein- and soy-containing diets. The present study demonstrates that chronic gentamicin-induced renal toxicity varies temporally according to the time of administration and that a mixed protein diet containing a lower fat level can protect against gentamicin-induced nephrotoxicity.
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Paquette M. The aftermath of violence. Perspect Psychiatr Care 2001; 37:113-4. [PMID: 15521310 DOI: 10.1111/j.1744-6163.2001.tb00642.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Lee DS, Dorian P, Downar E, Burns M, Yeo EL, Gold WL, Paquette M, Lau W, Newman DM. Thrombogenicity of radiofrequency ablation procedures: what factors influence thrombin generation? Europace 2001; 3:195-200. [PMID: 11467460 DOI: 10.1053/eupc.2001.0167] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIMS Thromboembolic complications have been reported after radiofrequency ablation but the low incidence of overt clinical events has been a limitation to the study of factors affecting thrombogenic risk. The aim of this study was to determine whether radiofrequency ablation has a procoagulant effect and to examine variables that affect thrombio generation. METHODS AND RESULTS Thirty-seven consecutive patients who underwent radiofrequency ablation were studied prospectively. Blood samples were assayed for thrombin-antithrombin III (TAT) and d-dimer (DD) at five different time points: (1) baseline; (2) after sheath insertion; (3) after electrophysiological study but before radiofrequency ablation; (4) at completion of the procedure; and (5) 24 h post-procedure. TAT levels were within the normal range at baseline and increased significantly after sheath insertion from 2.1 +/- 1.2 microg l(-1) to 13.3 +/- 16.0 microg l(-1) (P<0.01). Levels increased further to 24.0 +/- 19.9 microg l(-1) (P<0.01) after electrophysiological study but did not increase after radiofrequency ablation. TAT normalized at 24 h. DD increased significantly from baseline values (230.2 +/- 176.8 ng ml(-1)) to 285.4 +/- 237.4 ng ml(-1) (P=0.019) after sheath insertion. There was a further significant increase after electrophysiological study to 423.4 +/- 324.3 ng ml(-1) (P<0.01), and a slight but non-significant increase to 464.4 +/- 307.4 ng ml(-1) after radiofrequency ablation (P=0.159). DD remained elevated at 24 h. Procedure duration was the only variable that correlated with the relative increase in TAT and DD. The patients with the longest procedure durations had more catheters inserted, more radiofrequency applications and largely consisted of accessory bypass tract-mediated tachycardias. Heparin administration significantly blunted the relative increase in TAT after radiofrequency ablation (P=0.005). CONCLUSION Radiofrequency ablation procedures confer an increased risk of thrombosis. Catheterization and diagnostic study contribute largely to the thrombogenic stimulus. Thrombogenicity is increased in prolonged, complex procedures and is decreased in patients who have been administered heparin during the procedure.
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Savelieva I, Paquette M, Dorian P, Lüderitz B, Camm AJ. Quality of life in patients with silent atrial fibrillation. Heart 2001; 85:216-7. [PMID: 11156677 PMCID: PMC1729617 DOI: 10.1136/heart.85.2.216] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Baker B, Paquette M, Szalai JP, Driver H, Perger T, Helmers K, O'Kelly B, Tobe S. The influence of marital adjustment on 3-year left ventricular mass and ambulatory blood pressure in mild hypertension. ARCHIVES OF INTERNAL MEDICINE 2000; 160:3453-8. [PMID: 11112239 DOI: 10.1001/archinte.160.22.3453] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Of psychosocial stressors, job strain has been associated with a sustained increase in blood pressure. The impact of marital factors on blood pressure and target organ has not been explored. OBJECTIVES To evaluate whether marital adjustment, measured at baseline by self-report (Dyadic Adjustment Scale) influences left ventricular mass index (LVMI) and ambulatory blood pressure measured over 3 years in patients with mild hypertension. METHODS A prospective cohort study was conducted on 103 cohabiting males or females, including 72 with technically adequate echocardiograms, who at baseline were unmedicated, employed, and living with a significant other, all for a minimum of 6 months and had repeated elevated office diastolic blood pressure. MAIN OUTCOME MEASURES Left ventricular mass by M-mode echocardiography indexed to body surface area and blood pressure were measured by ambulatory blood pressure every 15 minutes (daytime) and hourly between 11 PM and 7 AM. RESULTS Marital adjustment, smoking, drinking, and baseline LVMI contributed significantly to the prediction of 3-year LVMI (semipartial correlation, sr(2) = 0.04, 0.07, 0.03, and 0.22; P =.03,.008,.08, and <.001, respectively) together accounting for 36% of the total variability in follow-up LVMI. Three-year ambulatory blood pressure measures were not significantly related to marital adjustment but there were correlations with Dyadic Adjustment Scale subscales. Low or high levels of spousal contact during 3-year ambulatory blood pressure monitoring were associated with an increase or decrease of 3-year, 24-hour diastolic blood pressure, consistent with the quality of marital adjustment (P =.04) or marital satisfaction (Dyadic Adjustment Scale subscale, P =.008). CONCLUSIONS In a cohort of subjects with mild essential hypertension, marital adjustment had an influence on 3-year LVMI. Depending on the quality of marital adjustment, spousal contact at 3 years was associated with an increase or decrease of 3-year diastolic blood pressure. Confirmation of these results, including objective marital assessment and the participation of normotensive subjects, is required. Arch Intern Med. 2000;160:3453-3458.
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Geist M, Newman D, Greene M, Paquette M, Dorian P. Permanent explantation of implantable cardioverter defibrillators. Pacing Clin Electrophysiol 2000; 23:2024-9. [PMID: 11202242 DOI: 10.1111/j.1540-8159.2000.tb00771.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although ICD therapy is seen as an irrevocable mode of therapy in most patients, a small number of patients do have their devices permanently explanted. The long-term outcome in these patients has not been described. The purpose of this single center study was to evaluate the long-term outcome of patients whose ICD was explanted and not replaced and to propose clinical variables that can be considered when making the decision to discontinue therapy. Ten of 323 (3.1%) patients in our ICD registry had their devices permanently explanted or turned off between 1986 and December 1998. The devices had been in place for 39 +/- 31 months preexplant. No patient had received appropriate therapy prior to surgery, which was indicated for infection or lead fracture. All patients are alive and well 75 +/- 30 months postexplant with 1 (10%) patient requiring late reimplantation. We reviewed the English language literature describing ICD explanation without replacement. A total of 151 patients were reported in eight studies and were followed for up to 30 months postexplant. Excluding patients with terminal illness or heart transplantation 57.6% survived without reimplantation. In selected patients, after not using an ICD for a long period and when clinical circumstances justify, device therapy may be discontinued with some degree of safety.
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Paquette M, Roy D, Talajic M, Newman D, Couturier A, Yang C, Dorian P. Role of gender and personality on quality-of-life impairment in intermittent atrial fibrillation. Am J Cardiol 2000; 86:764-8. [PMID: 11018197 DOI: 10.1016/s0002-9149(00)01077-8] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Patients with atrial fibrillation (AF) report impaired health-related quality of life (QOL). Differences between men and women with AF have not been described and personality attributes such as somatization (tendency to amplify benign bodily sensations) may mediate potential gender differences in QOL. Patients with AF (n = 264, 59% men) who participated in the Canadian Trial of Atrial Fibrillation (n = 403) completed validated QOL questionnaires at baseline, 3 months, and 12 months after antiarrhythmic drug treatment. Women were significantly older than men and a greater proportion had hypertension, but other cardiac variables did not differ between women and men. At baseline, after controlling for significant clinical and demographic factors, women reported worse physical health (p = 0.002) and functional capacity (p < 0.001), but not mental health or general well-being. Women also had more frequent and severe cardiac symptoms than men (both p < 0.001). Physical health improved significantly from baseline to 3 months for women (p = 0.002), but not for men (p = 0.066). Conversely, mental health improved for men (p = 0.007), but not for women. Cardiac symptom frequency and severity improved over time for women and men (all p < 0.001). Tendency to somatize predicted poor QOL, and women had higher scores than men (p = 0.023). However, after controlling for somatization, women still had worse physical function, functional capacity, and symptom burden than men. Independent of cardiac disease severity and age, women with AF had significantly more impaired QOL than men, specifically on domains related to physical rather than emotional functioning. Personality attributes may have a role in influencing QOL outcomes.
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Dorian P, Jung W, Newman D, Paquette M, Wood K, Ayers GM, Camm J, Akhtar M, Luderitz B. The impairment of health-related quality of life in patients with intermittent atrial fibrillation: implications for the assessment of investigational therapy. J Am Coll Cardiol 2000; 36:1303-9. [PMID: 11028487 DOI: 10.1016/s0735-1097(00)00886-x] [Citation(s) in RCA: 419] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES We sought to assess the impact of intermittent atrial fibrillation (AF) on health-related quality of life (QoL). BACKGROUND Intermittent AF is a common condition with little data on health-related QoL questionnaires to guide investigational therapies. METHODS Outpatients from four centers, with documented AF (n = 152), completed validated QoL questionnaires (Medical Outcomes Study Short Form 36 [SF-36], Specific Activity, Symptom Checklist, Illness Intrusiveness and University of Toronto AF Severity Scales). Comparison groups were made up of healthy individuals (n = 47) and four cardiac control groups: published (n = 78) and created for study (n = 69) percutaneous transluminal coronary angioplasty (PTCA); published heart failure (n = 216) and published postmyocardial infarction (MI) (n = 107). RESULTS Across all domains of the SF-36, AF patients reported substantially worse QoL than healthy controls (1.3 to 2.0 standard deviation units), with scores of 24%, 23%, 16% and 30% lower than healthy individuals on measures of physical and social functioning, mental and general health, respectively (all p < 0.001). Patients with AF were either significantly worse (p < 0.05, published controls) or as impaired (study controls) as either PTCA or post-MI patients on all domains of the SF-36 and the same as heart failure controls on SF-36 psychological subscales. Patients with AF were as impaired or worse than study PTCA controls on measures of illness intrusiveness, activity limitations and symptoms. Associations between objective disease indexes and subjective QoL measures had poor correlations and accounted for <6% of the total variability in QoL scores. CONCLUSIONS Quality of life is as impaired in patients with intermittent AF as in patients with significant structural heart disease. Patients' perception of QoL is not dependent on the objective measures of disease severity that are usually employed.
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Greene M, Newman D, Geist M, Paquette M, Heng D, Dorian P. Is electrical storm in ICD patients the sign of a dying heart? Outcome of patients with clusters of ventricular tachyarrhythmias. Europace 2000; 2:263-9. [PMID: 11227599 DOI: 10.1053/eupc.2000.0104] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Electrical storm in patients with implanted cardioverter defibrillators (ICDs) is purported to carry an ominous prognosis. METHODS AND RESULTS We retrospectively compared 40 patients with electrical storm (defined as three or more episodes of ventricular arrhythmia requiring ICD therapy in a 24 h period) with those only having isolated appropriate ICD therapy (n=57) and with patients having no or only inappropriate ICD therapy (n=125). All patients received ICDs for documented sustained VT or VF. There was no significant difference in age, sex, ejection fraction, total follow-up time, or underlying heart disease between any of the three groups. Patients who had electrical storm received their first appropriate ICD therapy 275 +/- 369 days post-implant (35% had storm as their first event) with storm occurring an average of 599 +/- 710 days post-implant. Patients had 1.5 +/- 1.0 storms in total (median= 1), with 55 +/- 91 episodes per storm. There were no significant differences in actuarial survival at 5-year follow-up between the three groups. Eighty percent of storm patients were alive 5 years post-implant. CONCLUSION Storm is a common occurrence in ICD patients, can occur at any time during the follow-up period, and does not independently confer increased mortality.
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Mok E, Paquette M, Thibault L. Effect of quipazine, a selective 5-HT3 agonist, on dietary self-selection of different macronutrient diets in male and female rats. Appetite 2000; 34:313-25. [PMID: 10888295 DOI: 10.1006/appe.2000.0321] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Macronutrient intakes, 2h and 12h, following administration of a selective 5-HT3 agonist, quipazine, N methyl, dimaleate (QUIPAZINE; 2.5, 5.0 and 7.5 mg/kg, i.p.) at dark onset were examined in three groups of adult male and female Wistar rats fed different sources of the three macronutrients: Group 1 (casein, corn starch, safflower oil), Group 2 (egg protein, corn starch/sucrose, lard) and Group S (casein hydrolysate, maltose dextrin, butter). QUIPAZINE decreased total food intake only in female rats from Group 1 (2 h) at a dose of 7.5 mg/kg and Group 2 (2h and 12h) with doses of 2.5 and 7.5 mg/kg. Intakes from corn starch and corn starch/sucrose diet (12h) were reduced in male and female rats, respectively, with doses of 2.5 and 7.5 mg/kg of QUIPAZINE. In conclusion, when provided with different sources of the three macronutrients, quipazine injection reduces specifically carbohydrate ingestion from corn starch-containing diets in male and female rats. Thus, the nature of the macronutrient source is of major importance to assess the effect of a drug on nutrient-specific selection.
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Nanthakumar K, Paquette M, Newman D, Deno DC, Malden L, Gunderson B, Gilkerson J, Greene M, Heng D, Dorian P. Inappropriate therapy from atrial fibrillation and sinus tachycardia in automated implantable cardioverter defibrillators. Am Heart J 2000; 139:797-803. [PMID: 10783212 DOI: 10.1016/s0002-8703(00)90010-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Inappropriate therapy from supraventricular tachyarrhythmias (atrial fibrillation [AF] and sinus tachycardia [ST]) in patients with implanted cardioverter defibrillators is a major challenge. We tested the performance of stability algorithms from 3 manufacturers for episodes of inappropriate therapy delivered because of AF and an onset algorithm for all episodes of inappropriate therapy caused by ST. METHODS Therapy was classified as caused by ventricular tachycardia (VT), ST, or AF from review of stored intracardiac electrograms, history, clinical information, and R-R data before study inception. By using 30 to 60 R-R intervals before therapy, sensitivity and specificity for a family of stability values and percentage of onset values were calculated for each manufacturer and receiver operating characteristic curves generated. RESULTS Of the 217 patients monitored, 62 (29%) received inappropriate therapy, and 40 had complete R-R information available. Of the 40 patients, 21 patients received therapy for AF, 19 for ST, and 1 patient for noise; 15 (38%) also received appropriate therapy for VT. We analyzed 83 episodes of VT from 18 patients, 94 episodes of AF from 21 patients, and 56 episodes of ST from 19 patients. Specificity, in the clinically relevant sensitivity range of >/=95%, was comparable across manufacturers at about 40%. An onset value of 80% was associated with 91% sensitivity and 95% specificity for the specific algorithm tested. CONCLUSIONS Inappropriate therapy is a common problem in implantable cardiac defibrillators. The performance of the stability algorithms used to differentiate AF from VT was less than ideal, though comparable across manufacturers. The onset algorithm accurately differentiates ST from VT.
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Nanthakumar K, Dorian P, Paquette M, Hutchison S, Andrews J, Newman D. Effect of physiological mechanical perturbations on intact human myocardial repolarization. Cardiovasc Res 2000; 45:303-9. [PMID: 10728350 DOI: 10.1016/s0008-6363(99)00261-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The objective of this study was to investigate the relationship between acute decreases in right ventricular volume during Valsalva strain (with resultant changes in autonomic neural tone) and measures of local endocardial repolarization time independent of heart rate and autonomic neural tone. METHODS Patients implanted with a stimulus to T wave (Stim-T) sensing pacemaker specially adapted to output a validate measure of beat to beat local repolarization (n = 9) performed Valsalva manoeuvers (40 mmHg for 15 s) while paced at a cycle length of 500 ms. Stim-T intervals were measured before and after autonomic blockade (Block: 0.03 mg/kg i.v. atropine +/- 0.15 mg/kg propranolol). Right ventricular end diastolic volume was estimated by simultaneous 2D-echocardiography. RESULTS Without autonomic blockade, compared to baseline, repolarization significantly prolonged during Valsalva strain (1.1 +/- 0.7%) and shortened during release (-1.4 +/- 1.0%). After block, strain related repolarization prolongation was also observed (1.0 +/- 0.6%), with significantly less release related repolarization shortening (-0.8 +/- 0.8%) compared to pre-block (P < 0.05). Right ventricular end diastolic volume decreased during strain by 11 +/- 10 and 9 +/- 16% from baseline, pre- and post-block respectively (P < 0.05). CONCLUSION In a chronically instrumented human model, an acute physiologic volume reduction modestly prolongs right ventricular repolarization independent of changes in rate or autonomic tone.
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Paquette M. Stepping into the future. Perspect Psychiatr Care 2000; 36:3-4. [PMID: 12035672 DOI: 10.1111/j.1744-6163.2000.tb00683.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Irvine J, Basinski A, Baker B, Jandciu S, Paquette M, Cairns J, Connolly S, Roberts R, Gent M, Dorian P. Depression and risk of sudden cardiac death after acute myocardial infarction: testing for the confounding effects of fatigue. Psychosom Med 1999; 61:729-37. [PMID: 10593621 DOI: 10.1097/00006842-199911000-00001] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES This study examined the impact of depressive symptoms and social support on 2-year sudden cardiac death (SCD) risk, controlling for fatigue symptoms. METHODS Myocardial infarction (MI) patients (N = 671) participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial completed measures of depression, hostility, and social support. RESULTS After controlling for significant biological predictors, psychosocial predictors of increased SCD risk in the survival analysis were greater social network contacts (RR = 1.04; 95% CI = 1.01-1.06; p < .007), lower social participation (RR = 0.98; 95% CI = 0.96-1.00; p < .05), and, in placebo-treated patients, elevated depressive symptoms (RR = 2.45; 95% CI = 1.14-5.35; p < .02). Fatigue was associated with SCD (RR = 1.31; 95% CI = 1.11-1.53; p < .001), and, when included in the model, diminished the influence of depression (RR = 1.73; 95% CI = 0.75-3.98; p = .20). When the cognitive-affective depressive symptoms were examined separately from somatic symptoms, there was a trend for an association between cognitive-affective symptoms and SCD in placebo-treated patients after controlling for fatigue (RR = 1.09; 95% CI = 0.99-1.19, p < .06). CONCLUSIONS Symptoms of depression and fatigue overlap in patients with MI. The trend for the cognitive-affective symptoms of depression to be associated with SCD risk, even after controlling for dyspnea/fatigue, suggests that the association between depression and mortality after AMI cannot be entirely explained as a confound of cardiac-related fatigue. The independent contribution of social participation suggests a role of both depressive symptomatology and social factors in influencing mortality risk after MI.
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Lee SD, Dorian P, Geist M, Davies E, Barr A, Dunne C, Paquette M, Newman D. Validation of a noninvasive measure of local myocardial repolarization in a conscious human model: adaptation of repolarization to changes in rate. J Cardiovasc Electrophysiol 1999; 10:1171-9. [PMID: 10517648 DOI: 10.1111/j.1540-8167.1999.tb00292.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
INTRODUCTION A commercial pacemaker sensor measure of the unipolar endocardial stimulus to T wave interval may accurately reflect changes in the monophasic action potential duration at 90% repolarization (APD90). This sensor system was used to study the kinetics of adaptation of repolarization duration to changes in heart rate in humans. METHODS AND RESULTS Patients were studied using an external pacemaker capable of displaying all stimulus to T wave intervals for each paced beat. Right ventricular stimulation was delivered via the pacemaker and compared simultaneously to APD90. Steady-state pacing was simulated by 60 seconds of pacing at cycle lengths (CLs) 350 to 700 msec. Adaptation to a new ventricular rate was analyzed with a sudden 200-msec decrease in CL. The relation between repolarization measure and steady-state CL (n = 16) was linear with a slope of 0.16 and 0.19 for APD90 and stimulus to T wave interval, respectively (P = NS). The adaptation of both repolarization measures to a sudden change in rate were best modeled by a biexponential function. Stimulus to T wave interval exhibited a parallel course to APD90, and an analysis of normalized differences between APD90 and stimulus to T wave interval followed an approximately normal distribution, with 93.5% of the paired differences within 2 SD of the mean. CONCLUSION A pacemaker sensor measure of stimulus to T wave interval accurately parallels APD90 during both steady-state and sudden changes in rate. Repolarization in human endocardium follows a linear relation to steady-state CL and adapts to a new rate with a biexponential function. This model represents a novel method for studying human cardiac repolarization.
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Irvine J, Baker B, Smith J, Jandciu S, Paquette M, Cairns J, Connolly S, Roberts R, Gent M, Dorian P. Poor adherence to placebo or amiodarone therapy predicts mortality: results from the CAMIAT study. Canadian Amiodarone Myocardial Infarction Arrhythmia Trial. Psychosom Med 1999; 61:566-75. [PMID: 10443767 DOI: 10.1097/00006842-199907000-00023] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE This study examined the relationship between adherence, mortality, and psychosocial factors. METHODS Subjects were 1141 patients participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial. Poor adherence to study medication (amiodarone or placebo), measured by pill count over 2 years, was defined as the lower 20th percentile of the pill count distribution. Predictors of adherence were also studied and included demographic and cardiac variables and, in a subset of participants (N = 671), measures of depression, distress, hostility, and social support. RESULTS In survival analysis controlling for cardiac and demographic variables, poor adherence in the placebo and amiodarone groups was associated with an increased risk of sudden cardiac death (relative risk (RR) = 2.11, 95% confidence interval (CI) = 1.03-4.56, p < .05; and RR = 3.15, 95% CI = 1.34-7.44, p < .01, respectively), total cardiac mortality (RR = 2.04, 95% CI = 1.12-3.72, p < .02; and RR = 2.49, 95% CI = 1.32-4.72, p < .01, respectively), and all-cause mortality (RR = 2.25, 95% CI = 1.27-3.97, p < .001; and RR = 2.34, 95% CI = 1.32-4.17, p < .004, respectively). Logistic regression analysis identified two predictors of poor adherence to placebo: age > 70 years (odds ratio = 2.18, 95% CI = 1.11-4.29, p < .03) and social activities in the month before the index heart attack (odds ratio = 1.02, 95% CI = 1.00-1.04, p < .05). CONCLUSIONS Poor adherence is associated with a greater risk of mortality. The relationship between adherence and social activities suggests a higher motivation to adhere to treatment in individuals more engaged in enjoyable activities.
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Nanthakumar K, Newman D, Paquette M, Greene M, Rakovich G, Dorian P. Circadian variation of sustained ventricular tachycardia in patients subject to standard adrenergic blockade. Am Heart J 1997; 134:752-7. [PMID: 9351744 DOI: 10.1016/s0002-8703(97)70060-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Morning peaks in the circadian variation of sustained ventricular tachycardia (VT) may reflect the contribution of sympathetic activation to onset of VT. We hypothesized that adrenergic blockade would eliminate this morning peak. Fifty-four patients using a defibrillator had 1114 time-stamped episodes of VT requiring therapy with a device: 1012 episodes with and 102 episodes without antiadrenergic medications. Nine patients had episodes both with and without antiadrenergic medication and were examined separately. In patients taking antiadrenergic agents, data fitted to a harmonic regression model revealed a morning peak at 9:00 AM (R2= 0.542; p < 0.05), with a secondary peak at 4 PM. Those not receiving antiadrenergic therapy had a similar morning peak. Antiadrenergic agents as used in standard clinical practice do not prevent circadian variation in onset of VT. This variation may be mediated by systems other than adrenergic receptor-linked activation or may reflect inadequacy of adrenergic blockade in standard clinical dosing.
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Sattar SA, Taylor YE, Paquette M, Rubino J. In-hospital evaluation of 7.5% hydrogen peroxide as a disinfectant for flexible endoscopes. THE CANADIAN JOURNAL OF INFECTION CONTROL : THE OFFICIAL JOURNAL OF THE COMMUNITY & HOSPITAL INFECTION CONTROL ASSOCIATION-CANADA = REVUE CANADIENNE DE PREVENTION DES INFECTIONS 1996; 11:51-54. [PMID: 8868803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The effectiveness of Sporox (Reckitt and Colman Inc, New Jersey), a 7.5% solution of hydrogen peroxide, was compared with that of Cidex (Johnson & Johnson), a 2% solution of alkaline glutaraldehyde, in the manual disinfection of flexible endoscopes at a large general hospital. For disinfection with Sporox, a soaking time of 10 mins at room temperature was used. The same disinfectant bath was used for nearly seven weeks and the Sporox level was monitored using reagent strips supplied with the product. Controls included endoscopes with precleaning (enzyme-detergent) but without any disinfection, and endoscopes that were precleaned and disinfected in Cidex only. A total of 3 mL of sterile normal saline was used for sampling each channel and immediately plated to detect aerobic and anaerobic bacteria as well as mycobacteria. There were 76 endoscopes sampled. Of these, 55 were disinfected in Sporox, 13 were disinfected in Cidex and eight were precleaned but not disinfected. None of the samples from endoscopes disinfected with either Sporox or Cidex yielded isolates generally regarded as pathogenic for humans. The findings of this in-hospital study indicate that Sporox is at least as efficacious as Cidex in the disinfection of flexible endoscopes between patients. In addition, the exposure time to Sporox was half as long compared with Cidex, and hydrogen peroxide is much less toxic to humans and the environment. Therefore, Sporox appears to have considerable potential as a safer substitute for glutaradehyde-based products in the decontamination of flexible endoscopes.
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Paquette M. [The organization of mental health services in the North-Shore region.]. SANTE MENTALE AU QUEBEC 1987; 12:144-9. [PMID: 16946976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
During the course of a regional symposium on mental health that took place at Sept-îles in October 1986, the author presented his views concerning the organization of mental health services in the North Shore region. In this article, he develops the two central ideas that supported his presentation. Firstly, he attempts to show to what extent it is imperative to deal with the issues surrounding alternatives to institutionalization; secondly, he attempts to show the importance of operationalizing services offered in small communities, in the area of preventive mental health care.
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